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High-dynamic-range
High dynamic range (HDR), also known as wide dynamic range, extended dynamic range, or expanded dynamic range, is a signal with a higher dynamic range than usual. The term is often used in discussing the dynamic ranges of images, videos, audio or radio. It may also apply to the means of recording, processing, and reproducing such signals including analog and digitized signals. Imaging In this context, the term ''high dynamic range'' means there is a large amount of variation in light levels within a scene or an image. The ''dynamic range'' refers to the range of luminosity between the brightest area and the darkest area of that scene or image. (HDRI) refers to the set of imaging technologies and techniques that allow the dynamic range of images or videos to be increased. It covers the acquisition, creation, storage, distribution and display of images and videos. Modern films have often been shot with cameras featuring a higher dynamic range, and legacy films can be post-conv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-exposure HDR Capture
In photography and videography, multi-exposure HDR capture is a technique that creates high dynamic range (HDR) images (or extended dynamic range images) by taking and combining multiple exposures of the same subject matter at different exposures. Combining multiple images in this way results in an image with a greater dynamic range than what would be possible by taking one single image. The technique can also be used to capture video by taking and combining multiple exposures for each frame of the video. The term "HDR" is used frequently to refer to the process of creating HDR images from multiple exposures. Many smartphones have an automated HDR feature that relies on computational imaging techniques to capture and combine multiple exposures. A single image captured by a camera provides a finite range of luminosity inherent to the medium, whether it is a digital sensor or film. Outside this range, tonal information is lost and no features are visible; tones that exceed the ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-dynamic-range Rendering
High-dynamic-range rendering (HDRR or HDR rendering), also known as high-dynamic-range lighting, is the rendering of computer graphics scenes by using lighting calculations done in high dynamic range (HDR). This allows preservation of details that may be lost due to limiting contrast ratios. Video games and computer-generated movies and special effects benefit from this as it creates more realistic scenes than with more simplistic lighting models. HDRR was originally required to tone map the rendered image onto Standard Dynamic Range (SDR) displays, as the first HDR capable displays did not arrive until the 2010s. However if a modern HDR display is available, it is possible to instead display the HDRR with even greater contrast and realism. Graphics processor company Nvidia summarizes the motivation for HDRR in three points: bright things can be really bright, dark things can be really dark, and details can be seen in both. History The use of high-dynamic-range imaging (HD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AVIF
AV1 Image File Format (AVIF) is an open, royalty-free image file format specification for storing images or image sequences compressed with AV1 in the HEIF container format. It competes with HEIC, which uses the same container format built upon ISOBMFF, but HEVC for compression. Version 1.0.0 of the AVIF specification was finalized in February 2019. Version 1.1.0 was finalized in April 2022. In a number of tests by Netflix in 2020, AVIF showed better compression efficiency than JPEG as well as better detail preservation, fewer blocking artifacts and less color bleeding around hard edges in composites of natural images, text, and graphics. AVIF support is available in all the major web browsers (i.e. over 93% of all web browsers). Features The AV1 Image File Format supports: * Multiple color spaces, including: ** HDR (with PQ or HLG transfer functions and BT.2020 color primaries, as part of BT.2100) *** Supports HDR gain map approach, backwards compatible with SDR di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby Vision
Dolby Vision is a set of technologies developed by Dolby Laboratories for high dynamic range (HDR) video. It covers content creation, distribution, and playback. It includes dynamic metadata that define the aspect ratio and adjust the picture based on a display's capabilities on a per-shot or even per-frame basis, optimizing the presentation. Dolby Vision was introduced in 2014, making it the first available HDR format. HDR10+ is a competitor HDR format that also uses dynamic metadata. Dolby Vision IQ is an update designed to optimize Dolby Vision content according to the ambient light. Dolby Cinema also uses Dolby Vision in conjunction with Dolby Atmos sound systems, though because of the use of 2.6 gamma and thus 48 nits in SDR cinemas, the 108 nits used in Dolby Cinema is already HDR. Description Dolby Vision allows for a maximum resolution of 8K, up to 12-bit color depth, and maximum peak brightness of 10,000 nits. However, according to the Dolby Vision white pap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tone Mapping
Tone mapping is a technique used in image processing and computer graphics to map one set of colors to another to approximate the appearance of high-dynamic-range (HDR) images in a medium that has a more limited dynamic range. Print-outs, CRT or LCD monitors, and projectors all have a limited dynamic range that is inadequate to reproduce the full range of light intensities present in natural scenes. Tone mapping addresses the problem of strong contrast reduction from the scene radiance to the displayable range while preserving the image details and color appearance important to appreciate the original scene content. Inverse tone mapping is the inverse technique that allows to expand the luminance range, mapping a low dynamic range image into a higher dynamic range image. It is notably used to upscale SDR videos to HDR videos. Background The introduction of film-based photography created issues since capturing the wide dynamic range of lighting from the real world on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard-dynamic-range Video
Standard-dynamic-range video (SDR video) is a video technology which represents light intensity based on the brightness, contrast and color characteristics and limitations of a cathode ray tube (CRT) display. SDR video is able to represent a video or picture's colors with a maximum luminance around 100 cd/m2, a black level around 0.1 cd/m2 and Rec.709 / sRGB color gamut. It uses the gamma curve as its electro-optical transfer function. The first CRT television sets were manufactured in 1934 and the first color CRT television sets were manufactured in 1954. The term "standard-dynamic-range video" was adopted to distinguish SDR video from high-dynamic-range video (HDR video), a new technology that was developed in the 2010s to overcome SDR's limits. Technical details Transfer function Conventional gamma curves: * Opto-electronic transfer function (OETF): ** Rec. 601 (analog video signals in SD-TV digital video form) ** Rec. 709 ( HD-TV) ** Rec. 2020 ( UHD-TV) ** sRGB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-dynamic-range Television
High-dynamic-range television (HDR-TV) is a technology that uses high dynamic range (HDR) to improve the quality of display signals. It is contrasted with the retroactively-named standard dynamic range (SDR). HDR changes the way the luminance and colors of videos and images are represented in the signal and allows brighter and more detailed highlight representation, darker and more detailed shadows, and more intense colors. HDR allows compatible displays to receive a higher-quality image source. It does not improve a display's intrinsic properties (brightness, contrast, and color capabilities). Not all HDR displays have the same capabilities, and HDR content will look different depending on the display used, and the standards specify the required conversion depending on display capabilities. HDR-TV is a part of HDR imaging, an end-to-end process of increasing the dynamic range of images and videos from their capture and creation to their storage, distribution and display. Often, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HDR10
HDR10 Media Profile, more commonly known as 'HDR10'', is an open high-dynamic-range video (HDR) standard announced on 27 August 2015, by the Consumer Electronics Association. It is the most widespread HDR format. HDR10 is not Backward compatibility, backward compatible with Standard-dynamic-range video, SDR. It includes HDR static metadata but not HDR dynamic metadata, dynamic metadata. PQ10 refers to an HDR10 format which does not include any metadata. Technical details HDR10 is defined as: * EOTF: SMPTE ST 2084 (Perceptual quantization, PQ) * Bit depth: 10 bit * Color primaries: Rec. 2020, ITU-R BT.2020 (identical to Rec. 2100, BT.2100 primaries) * Static metadata: SMPTE ST 2086 (mastering display color volume), MaxFALL (maximum frame-average light level), and MaxCLL (maximum content light level) * Color sub-sampling: 4:2:0 (for compressed video sources) PQ10 refers to an HDR format that uses PQ, 10-bit and Rec. 2100 color primaries without having any metadata. HDR10 is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HDR10+
HDR10+ is a High-dynamic-range video, high dynamic range (HDR) video technology that adds HDR dynamic metadata, dynamic metadata to HDR10 source files. The dynamic metadata are used to adjust and optimize each frame of the HDR video to the consumer display's capabilities in a way based on the content creator's intentions. HDR10+ is an alternative to Dolby Vision, which also uses dynamic metadata. HDR10+ is the default variant of dynamic metadata as part of the HDMI#Version 2.1, HDMI 2.1 standard. HDR10+ Adaptive is an update designed to optimize HDR10+ content according to the Available light, ambient light. HDR10+ Gaming is an HDR standard optimized for gaming, providing accurate HDR gaming images with low latency, variable refresh rate (VRR) and high frame rate. Description HDR10+, also known as HDR10 Plus, was announced on 20 April 2017, by Samsung and Amazon Video. HDR10+ updates HDR10 by adding dynamic metadata that can be used to more accurately adjust brightness levels up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exposure (photography)
In photography, exposure is the amount of light per unit area reaching a frame (photography), frame of photographic film or the surface of an electronic image sensor. It is determined by shutter speed, lens f-number, and scene luminance. Exposure is measured in unit of measurement, units of lux-seconds (symbol lxs), and can be computed from exposure value (EV) and scene luminance in a specified region. An "exposure" is a single shutter cycle. For example, a long-exposure photography, long exposure refers to a single, long shutter cycle to gather enough dim light, whereas a multiple exposure involves a series of shutter cycles, effectively layering a series of photographs in one image. The accumulated ''photometric exposure'' (''H''v) is the same so long as the total exposure time is the same. Definitions Radiant exposure Radiant exposure of a ''surface'', denoted ''H''e ("e" for "energetic", to avoid confusion with Photometry (optics), photometric quantities) and measured in , i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
